Primary malignant tumours associated with renal cell carcinoma.

Of 360 patients with primary renal cell carcinoma seen at the Vancouver General Hospital between 1957 and 1976, 33 had associated primary malignant lesions. A review of the 166 patients who had ablative surgery revealed that they were four times more likely to have a synchronous primary malignant tumour than the other patients. The incidence of asynchronous primary malignant tumours was not increased. This may be related to the fact that the patients' full life charts were not available. In 18 patients dying of other causes in whom an incidental renal cell carcinoma was found, 5 (28%) died of other malignant tumours. In a comparable age group from the general population, 19% are at risk of death from malignant disease. The frequency of synchronous contralateral renal cell carcinoma in our series was 50 times greater than the frequency of primary renal cell carcinoma in a corresponding sector of the general population.